Internal combustion engines include fuel injectors that are structured to inject fuel into combustion chambers of the engine. Properly functioning fuel injectors inject the fuel in an optimal atomized-mist that burns cleanly to optimize engine performance and minimize emissions. However, deposits can build up on fuel injectors over time from impurities in the fuel. Such deposits can hinder operation of the precisely-controlled fuel injectors, thereby reducing engine performance, such as through reduced output power, increased frequency of hard starts, reduced fuel economy, and increased emissions.